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USS Cod (SS-224) / Re: Name That Radio
« on: June 18, 2012, 08:48:42 PM »
I somehow missed this post before, but here is the history of the AM Broadcast Band here in the U.S.
* The Standard Broadcast Band began in 1921 with just one frequency (833 kHz).
* In December 1921, 619 kHz was added for Weather and Market reports.
* In September 1922, 750 kHz was added as a new "Entertainment" frequency.
* On May 15, 1923, the Standard Broadcast Band was expanded to 550-1360 kHz using 10 kHz steps.
* In April 1925, this was further expanded to 550-1500 kHz.
* November 11, 1928 saw the first big "realignment" as the FRC shifted many stations, and deleted others, in an attempt to reduce interference.
* On March 29, 1941, the band was extended to 550-1600 kHz. On this date, the NARBA frequency shift changed many stations spot on the dial.
* In the early 1950s, the band was extended to 540-1600 kHz. The first 540s appeared in 1954 or 1955.
* In mid-1961, most Class IV stations were permitted to increase power from 250 Watts to 1/.25 kW.
* In 1983, most Class IV stations were permitted to increase power from 1/.25 kW to 1 kW.
* In 1995, the FCC again extended the Standard Broadcast Band to 540-1702 kHz.
* The Standard Broadcast Band began in 1921 with just one frequency (833 kHz).
* In December 1921, 619 kHz was added for Weather and Market reports.
* In September 1922, 750 kHz was added as a new "Entertainment" frequency.
* On May 15, 1923, the Standard Broadcast Band was expanded to 550-1360 kHz using 10 kHz steps.
* In April 1925, this was further expanded to 550-1500 kHz.
* November 11, 1928 saw the first big "realignment" as the FRC shifted many stations, and deleted others, in an attempt to reduce interference.
* On March 29, 1941, the band was extended to 550-1600 kHz. On this date, the NARBA frequency shift changed many stations spot on the dial.
* In the early 1950s, the band was extended to 540-1600 kHz. The first 540s appeared in 1954 or 1955.
* In mid-1961, most Class IV stations were permitted to increase power from 250 Watts to 1/.25 kW.
* In 1983, most Class IV stations were permitted to increase power from 1/.25 kW to 1 kW.
* In 1995, the FCC again extended the Standard Broadcast Band to 540-1702 kHz.
